1. Field of the Invention
This invention generally relates to communication systems. In particular, an exemplary embodiment of this invention relates to the detection of one or more devices that either directly or indirectly impose nonlinear effects on communication signals.
2. Description of Related Art
One of the most problematic aspects of Digital Subscriber Line (DSL) communications is the in-home environment. One of the most troubling aspects of the in-home environment is the presence of unfiltered devices connected to the telephone line such as telephones, answering machines and fax machines. Many of these devices impose nonlinear behavior on transmitted signals. Harmonic frequencies arising from these nonlinearities generate a disturbance that is often the dominant noise source limiting data rates and loop reach.